By Jennifer K. Nelson, R.D., Director of Clinical Dietetics, Mayo Clinic, Rochester, Minn. QUESTION: What's the difference between whole grain and high fiber?
ANSWER: One is a major, though nonexclusive, vehicle for the other. Whole grains -- the unadulterated seeds of cereal grasses such as wheat, rice and barley -- are good sources of fiber, and they are rich in other nutritionally valuable things, as well. Whole grains are not the only sources of fiber. Other plant foods, such as fruit and vegetables, are high in fiber, too.
Fiber, which comes in two forms (water-soluble and water-insoluble), is the part of plant food that your body cannot digest. Nonetheless, fiber performs some important bodily functions. When soluble fiber dissolves it forms a spongy complex that helps lower blood cholesterol by soaking up surplus cholesterol and removing it from the body. Soluble fiber also slows absorption of sugar, thereby lowing blood sugar levels. These effects reduce the risk of heart disease, diabetes and other illnesses.
Insoluble fiber, meanwhile, holds onto water, which serves to bulk up and soften stools so that they easily pass through and out of the digestive system. As a result, the likelihood of problems such as hemorrhoids and constipation, as well as more serious gastrointestinal ailments, is lowered.
Though all plant foods contain both soluble and insoluble fiber, most whole grains -- such as whole wheat and brown rice -- are particularly rich in insoluble fiber. In contrast, fruits, vegetables, legumes (beans, for example) oats and barley are richer in soluble fiber. Thus there is no one "best" source of fiber. We must eat a variety of healthful foods in order to derive all of fiber's benefits. In a whole grain, most of the fiber is contained in the bran, which is the outer layer of the seed. But the bran is also an abundant source of niacin, thiamin, riboflavin, magnesium, phosphorus, iron and zinc. When grains are milled --processed, for example, into white flour or white rice -- the bran is removed. The second part of a whole grain is the germ, from which a new plant sprouts. The germ is rich in many of the same nutrients that are found in the bran, and it also contains some protein, fat, vitamin E and most everything else the embryonic stage of the plant needs in order to grow. The germ, too, is removed when whole grains are converted to refined grains. Next: Incentives for healthier eating habits >
Source: Health & Wellness
